Thermal mechanical mineral piercing



May 30, 1967 ARNOLD ET AL 3,322,213

THERMAL MECHANICAL MINERAL PIERCING Filed March 51, 1964 INVENTOR5 CORNELIUS S. ARNOLD HAROLD C. ROLSETH AT TORNEV United States Patent 3,322,213 THERMAL MECHANICAL MINERAL PIERCING Cornelius S. Arnold, Cranford, and Harold C. Rolseth,

New Brunswick, N.J., assignors to Union Carbide Corporation, a corporation of New York Filed Mar. 31, 1964, Ser. No. 356,301 3 Claims. (01. 175-14) This invention relates to thermal mechanical piercing an elongated hole in a mineral body.

In the flame piercing of minerals with a blowpipe, high temperature flames are applied to a surface of the mineral to heat the same to an elevated temperature sufficiently high to cause said surface to spall o-r melt to form the hole. The mineral particles so produced are removed by entraining the same in the gases produced by the flames, which gas entrained particles are exhausted from the hole.

The application of the flames is continued to advance the hole until a stratum of different compositions is encountered. This stratum may be of greater resistance to the effect of the flames, or an open stratum which dissipates the flames. These or other conditions may cause a necking down in the hole, forming a flame resistant collar of reduced diameter.

For the removal of such collars, the blowpipe has been provided with circumferentially spaced longitudinally extending reamers. However, these reamers have been ineflicient and slow, and of extremely short life in their scraping .action on the solid rock.

The main objects of the present invention are therefore to expedite the removal of such collars while continuing the action of the flames, and to increase the life of the collar removing means.

According to the present invention, such collars are removed by rolling contact mechanical impact applied automatically when the hole encounters such collar, which rolling contact rapidly and efliciently removes the material forming the collar, and greatly reduces the delay in the advancement of the hole formed by the flames.

For this purpose, the blowpipe is provided with planetary cutters journaled on the outside of the blowpipe and circumferentially spaced around the blowpipe and spaced above the blowpipe flame orifices, and the blowpipe is rotated to cause rolling contact mechanical impact of the cutters with the material of the collar.

Once the collar is removed and the flames encounter less resistant material therebeyond, the hole formed by the flames is generally larger than the path of the cutters, so that the cutters idle until another collar is encountered.

The planetary cutters present the problems of protection from the heat of the flames, and the removal of the heat generated by the abrasion or impact of the cutters with the material or friction of the bearings for the cutters.

It is, therefore, another object of the invention to supply cooling fluid to the cutters, particularly to the cutting teeth thereof. This is preferably accomplished by projecting jets of cooling fluid onto the teeth of the cutters from the cooling jacket of the blowpipe burner.

In the drawing, the single figure is a vertical axial section through a blowpipe burner and drill head according to and for carrying out the method of the preferred em- 'bodiment of the present invention.

The thermal mechanical piercing apparatus comprises a 'blowpipe consisting essentially of a burner and a bit head 12. The blowpipe is provided with a passage for oxidizing gas, and a fuel passage 16 for supplying the burner nozzle 18. The fuel passage 16 leads to a fuel injector 19, and the oxidizing gas passage 15 leads to the space around the injector 19, to discharge atomized fuel 3 ,3-22 ,2 l3 Patented May 30, 1967 into the combustion chamber 20 inside the nozzle 18 above the orifice tip 22.

The orifice tip 22 extends below the bit head 12, and this tip is provided with flame ports 23, preferably three in number, spaced apart, and diverging at an angle of not more than 45 to the blowpipe axis, for directing flames onto the surface of the mineral body.

The bit 12 encloses the burner 10 and is provided with inwardly converging axles 26 on which are journaled planetary drill bits 28 for rolling contact with the mineral body. These cutters are preferably three in number spaced 120 apart and alternating with the spacing of flame ports 23.

Cooling water is supplied to the cooling jacket 32 between the burner 10 and the bit head 12 from which drillings 34 project streams of cooling water directly onto the top of the teeth of the cutters 28. Cooling water from the jacket 32 also enters the burner assembly through holes 36 from which the flow is through boring 38 to annulus 40, from which a drilling 42 conveys the water to a well 50 located at the center just behind the burner face. From this well, drillings 44 direct streams of cooling water directly onto the bottoms of the cutter teeth 28.

In operation, the blowpipe is let down close to the mineral surface, rotation of the blowpipe is started, and the process fluids supplied to the blowpipe are turned on. Oxidizing gas through passage 15 and fuel through passage 16 are mixed at the fuel injector 19, and discharged into chamber 20 where they are ignited and burned. The hot products of combustion are discharged through flame ports 23 forming high temperature, high velocity flames.

The supply of fuel and oxidizing gas is at a substantially constant rate, and the flames are continuous and at substantially constant temperature. The blowpipe is rotated at substantially constant speed in the range of from 15 to 45 revolutions per minute.

The intense heat produced which is directed against the mineral surface causes spalling or melting to form the hole. The mineral particles so produced are removed by entraining the same in the gases produced by the flames, which gas entrained particles are exhausted from the hole. i

The application of the divergent flames produces a hole larger than the blowpipe and the bit head 12, and the blowpipe is lowered as the hole progresses until a stratum of difierent composition is reached, which forms a flame resistant collar of smaller diameter. The lowering of the blowpipe automatically brings the planetary cutters 28 into engagement with such collar, and the rotation of the blowpipe causes rotation of the cutters with mechanical impact upon the mineral of the collar to rapidly and efiiciently remove the same.

Once the collar is removed and the flames encounter less resistant material therebeyond, the hole is generally larger than the path of the cutters, which therefore idle until another collar is encountered.

The cooling water is employed to cool the burner 10 and the bit head 12, and is also discharged directly onto the teeth of cutters 28. That discharged through bit head drillings 34 directly onto the top of cutter teeth forms jets substantially radial to the bearing axis. That discharged through drillings 44 forms jets divergent from the bearing axis and impinging upon the bottoms of the cutter teeth.

What is claimed is:

1. Method of thermal mechanical piercing an elongated vertical hole in a mineral body, which comprises applying flames to heat the mineral surface to an elevated temperature sufficiently high to cause said surface to spall or melt, thereby forming a hole solely by the action of said flames and the ejection of mineral particles so formed with the gaseous products exhausted from the hole, and removing any more resistant mineral from the wall of the hole by subjecting said resistant mineral to rolling contact mechanical impact.

2. Method of flame piercing an elongated hole in a mineral body, which comprises applying to said body a high temperature flame to heat a surface thereof to an elevated temperature sufficiently high to cause said surface to spall or melt to form the hole, while removing the mineral particles from said surface by exhausting from the hole the gases produced by the flame, continuing the application of said flame until the hole reaches a stratum which causes the hole to neck down and form a flame resistant collar, and thereupon automatically applying rolling contact mechanical impact to said collar to remove the same while continuing the action of said flames.

3. Apparatus for thermal mechanical piercing a hole in a mineral body, comprising an internal combustion burner having divergent flame ports, a

bit head surround- 20 ing said burner, planetary roller cutters journaled on said bit head, said roller cutters having teeth with the cutting edges thereof terminating in a horizontal plane located above the horizontal plane of said flame ports, and means for directing jets of cooling fluid onto the outside of said roller cutters whereby said cutters only come into c0ntact with said mineral body when .a collar is formed around the periphery of said hole.

References Cited UNITED STATES PATENTS 1,284,398 11/1918 McKinlay 17511 X 3,182,734 5/ 1965 Scott 17515 X 3,205,953 9/1965 Ferrabee 17515 X 3,212,592 10/ 1965 Rolseth et al 175-14 CHARLES E. OCONNELL, Primary Examiner. D. H. BROWN, Assistant Examiner. 

1. METHOD OF THERMAL MACHANICAL PIERCING AN ELONGATED VERITCAL HOLE IN A MINERAL BODY, WHICH COMPRISES APPLYING FLAMES TO HEAT THE MINERAL SURFACE TO AN ELEVATED TEMPERATURE SUFFICIENTLY HIGH TO CAUSE SAID SURFACE TO SPALL OR MELT, THEREBY FORMING A HOLE SOLELY BY THE ACTION OF SAID FLAMES AND THE EJECTION OF MINERAL PARTICLES SO FORMED WITH THE GASEOUS PRODUCTS EXHAUSTED FORM THE HOLE, AND REMOVING ANY MORE RESISTANT MINERAL FROM THE 